Method of casting glass-molds.



H. DAMAN.

METHOD OF CASTING GLASS MOLDS.

APPLICATION FILED NOV. 23, I917.

Patented Feb. 25, 1919.

FEB.E.

INVENTOR WITNESSES HERBERT DAMAN, OF ROCHESTER, PENNSYLVANIA.

METHOD OF CASTING GLASS-MOLDS.

Specification of Letters Patent.

Application filed November 23, 1917. Serial No. 203,509.

To all whom it may concern:

Be it known that I, HERBERT DAMAN, re-

siding at Rochester, in the county of Beaver and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Methods of Casting Glass-Molds, of which improvements the following is a specification.

The object of my invention is to provide a method of casting annular cast-iron glassmolds, whereby such molds will be rendered much more suitable and efiicient for their intended purpose than are the molds as they are now cast in actual practice.

My invention is predicated upon my discovery that by casting such glass-molds in molds the inner and outer walls of which are formed of chill irons, the texture and physical characteristics of the iron forming the glass-molds, and particularly the portion of the iron forming the interior surfaces of the glass-molds, are such that when the glass-molds are put in use the breakage of the glass articles molded therein is much less than thebreakage of such articles when molded in the glass-molds heretofore used, and furthermore that the articles molded therein have a superior surface.

While my invention is unlimited to glassmolds for any specific purpose, it finds particular adaptability to glass-molds used in pressing andblowing articles such as bottles, cans, etc. With respect to glass-molds for such purposes, I have made the further di.scovery that, to obtain the best results, the outer chill iron of the casting mold should have a thiclmess of not less than about one fifth and not more than about one half of the average wall thickness of the glass-mold.

Y My invention may be best understood by describing it in detail with reference to the mold shown in the accompanying drawing, of which Figure 1 is a vertical central sectional view of the mold, and Fig. 2 a horizontal sectional View taken on the line I'I-II, Fig. 1. However, it will be understood that difi'erent specific forms of molds than that shown herein may be used in the practice of my invention.

The shape of the glass-molds. adapted to be cast in the mold shown herein is indicated by the cavity A. The mold comprises essentially an outer shell 1, preferably formed of two parts as shown in Fig. 2, and a central post or core 2. Both the shell and core are chill iron. Specifically, they are made of cast iron, and the thickness of the shell is not less than one fifth (preferably one third as indicated in the drawings) or more than one half the average wall thickness of the glass mold castbetween such shell and the core. The shell and core are preferably placed within a cheek 3, a cope 4 and a drag 5, all formed of sand and provided with suitable casting sprues 6.

In castingv a glass mold by means of the mold shown herein, the molten iron is poured into the sprues 6 in the usual man ner until the cavity A is filled, the entrapped gas and air escaping through the sand cope '4. When the iron solidifies, the casting is removed from the mold by separating the shell sections 1 and withdrawing the core 2. The glass-mold casting may then be machined in the usual manner.

The glass-mold thus cast is, as compared with the usual sand-cast glass-molds, dense, tough, and free from defects incident to graphitic carbon in large amounts; and the surface is clean and smooth and not disfigured by objectionable hair cracks. As a consequence of these characteristics, I have found, as already stated, that when the glass-mold is put in use the breakage of the glass articles molded therein is much reduced as compared to the breakage of such articles molded in the glass-molds heretofore used. These characteristics of the glass-mold I have found to be due to the outer chill iron or shell .1. When such shell is omitted and the inner cavity of the glassmold is formed by a cast-iron core 2, the resulting glass-mold does not have the above explained desirable characteristics. Furthermore, I have found that such characteristics cannot be obtained, in glass-molds of the general shape shown herein, when the thickness of the chill iron or shell 1 is, as compared with the average thickness of Patented Feb. 25, 1919.

the glass-mold wall, otherwise than within casting the molten iron between said inner or core of a chill iron, and casting the 10 and outer chill irons. molten iron between said inner and outer 2. The herein described method of casting chill irons.

an annular cast-iron glass-mold, which ioon- In testimony whereof I have hereunto set sists in forming the outer mold wallof a my hand. I chill iron the thickness of which is not less HERBERT DAMAN. than about one fifth and not more than Witnesses: about one half the average wall thickness of JOSEPH M. EAKIN,

the glass-mold, forming the inner mold wall S. A. ARMSTRONG. 

